Disazo dyestuffs



The present invention concerns new disazo dyestuffs, processes for the production thereof, a process for the dyeing of fibres containing natural or synthetic polyamide as well as, as industrial product, the material dyed with the aid of these dyestuffs.

It is well known that optimal wet fastness properties can be obtained on natural and synthetic polyamide fibers only when dyestuffs are used which draw from a neutral bath. This requires the observation of close limit conditions in particular in dyeing Wool and thus considerably complicates the dyeing with neutral-drawing dyestuffs. Moreover, the dyeing from a neutral bath has the drawback of disadvantageously influencing the physical properties of wool and even particularly damaging the latter. [C. L. Bird, The Theory and Practice of Wool Dyeing, pages 60-64, (1947).] It is, therefore, preferred to dye wool at its isoelectric point. However, this requires the use of dyestuffs drawing from a weakly acid to acid bath, and these dyestuffs suffer from the drawback that it is not possible to obtain dyeings with optimal wet fastness properties; if, in an attempt to solve this problem, neutral-drawing dyestuffs are used for dyeing from an acid bath, the resulting dyeings are not level.

I It is, therefore, an object of the present invention to provide a dyestuif class which affords a combination of the following two advantages: firstly, these dyestuffs must dye from a weakly acid to acid dyebath, and, secondly, they must yield dyeings of optimal wet fastness properties.

It has been found that, surprisingly, this combination of desirable properties is possessed by yellow disazo dyestufi'is according to this invention, which are obtained by coupling (a) One mole of a tetrazotised diamine of formula HzN NHg ll n (I) wherein n is 1 or, preferably, 2, and wherein the benzene rings A and B can be further substituted as explained below.

(b) With two moles of a l-phenyl-3-methyl-5-amino pyrazole the benzene ring of which can be further substituted as explained below to form a compound of formula wherein X is a water-solubilizing group which dissociates acidically in water, namely --COOH or, preferably -SO H (or their sodium, potassium or ammonium salts), .m is an integer ranging from 1 to 4, and preferably 2, n has the same meaning as in Formula I and either the aforesaid diamine of Formula I, or the 5-aminopyrazole coupling component, or both, contain the said United States Patent 0 ice substituent or substituents X, so that the dyestufi of Formula II above contains at least one of said watersolubilizing, acidically-dissociating groups, preferably a sulfonic acid group.

Apart from the latter group or groups, if such is present therein; the' benzene rings of the diamine of Formula I can be unsubstituted, or they can be substituted further with from one to preferably not more than two of the following substituents which are compatible with the process according to the invention, and are designated in this specification and in the appended claims as monovalent azo-compatible substituents and are alkyl with maximally 4 carbon atoms, preferably methyl or ethyl, chlorine, bromine, one or at most two sulfamyl or lower alkyl-sulfonyl. specification and in the appended claims designates alkyl :with from 1 to 4 carbon atoms.

The benzene ring (D, E) of the l-phenyl-3-methyl-5- amniopyraz ole used according to the invention as coupling component'can be unsubstituted, or it can be substituted-apart from the above-mentioned water-solubilizing substituent or substituents X, if it is desired that these be present in the coupling component-with one or two of the substituents Whose presence in the coupling component is compatible with the presence according to the present invention and which are designated in this specification and in the appended claims as monovalent coupling-compatible substituents, which are alkyl with maximally 4 carbon atoms, preferably methyl and ethyl, benzyl, methylbenzyl, chlorobenzyl, phenyl, methylphenyl, chlorophenyl, bromophenyl, methoxy, ethoxy, phenoxy, chlorophenoxy, bromophenoxy, sulfophenoxy, methylphenoxy, -SO NH N-monoand N-di-(lower alkyl)-sulfamyl respectively, N-alkyl-N-phenylsulfonyl with a total of maximally 10 carbon atoms, lower alkyl- ,sulfonyl,.phenylsulfonyl, methylphenylsulfonyl, chlorophenylsulfonyl, sulfophenylsulfonyl, fluorine, chlorine, bromine and cyano, with the proviso that in the end products the above defined total of water-solubilising groups which dissociate acidically in water, does not exceed the limits given above. I

The tetrazotised diamine of Formula I is coupled at a temperature of about -10 to C., and preferably at +10 to 25 C. with the 1-phenyl-3-methyl-5- arninopyrazole as defined above, advantageously in an aqueous-acid medium, while, if desired, gradually buffering the acid with an agent which raises the pH value, e.g. with an alkali metal salt of a low-molecular fatty acid such as sodium acetate and, if necessary, in the presence of organic solvents which are miscible with water such as low fatty alcohols, e.g. methanol or ethanol or low aliphatic ketones such as acetone.

A modification of the process for the production of (ii). N

disazo dyestuffs according to the invention consists in coupling, in an acid medium,one mol of a tetrazotised diamine of Formula I with two mols of a compound of Lower alkyl as used in this I wherein W is the oxo or imino group, to form a disazo dyestuif of Formula IV @NH-NH:

in an acid medium, to form a compound of Formula II. The new compounds of Formula I, and particularly They yield dyeings with the above-mentioned wet fastness properties, which comprise in particular fastness to washing, to alkali, to milling,.to transpiration and to sea water. They are also distinguished by their excellent solubility in water and the resistance to flocculation of these dyestuffs in hard water. The dyestuffs are also very fast to light, to steaming and are excellently whitedischargeable.

Another advantageous feature of these dyestuffs is their excellent reserve for cotton, viscose and acetate yarn, polyethyleneglycol terephthalate and poly-aorylonitrile fibers (Terylene and Orlon). They are thus very suitable for dyeing blends of wool or synthetic polyamide fibers, especially nylon, with the aforesaid reserved fibers.

Further details can be seen from the following nonlimitative examples. W Where not otherwise expressly stated, parts are given as parts by weight. The temperatures are in degrees centigrade. The relationship of parts by weight to parts by volume is as that of grams n is one of the numerals 1 and 2,

Z is either hydrogen, chlorine, bromine or alkylwith maximally 4 carbon atoms,

Y is either hydrogen, chlorine, bromine, alkyl with maximally 4 carbon atoms, phenoxy, chlorophenoxy, bromophenoxy, methylphenoxy, phenylsulfonyl, meth ylphenyl-sulfonyl, chlorophenylsulfonyl, di(N- alkyl)- sulfamyl with a total of at most 8 carbon atoms, N- phenyl-N-lower alkyl-sulfamyl, or N-lower alkylsulfamyl, and 7 Y is either hydrogen, chlorine or bromine or lower alkyl,

draw very satisfactorily on to fibers containing natural or synthetic polyamide from a weekly acid, for instance an acetic acid bath, and they produce very pure yellow dyeings which, in spite of the nature of the bath, are unexpectedly of excellent wet fastness properties and are very fast to light.

The novel dyestuffs according to the invention are also distinguished from hitherto available wool dyes by their very good levelling power, which latter is, to a considerable extent, independent of the dyeing conditions used. Thus it is excellent over a wide pH range of the dyebath, in particular between about 2 and 6.5.

Dye-stufiis according to the invention with optimal properties, among those described above, are the dyestuffs of the formula Z is either hydrogen or chlorine, Y is either hydrogen, chlorine or methyl, and Y is either hydrogen or chlorine.

12.4 parts of 3,3-diamino-1,1'-diphenylsulphone are dissolved at 35-40 in 500 parts of water and 40 partsof concentrated hydrochloric acid. The solution is then cooled to 0 to 5 and the diamine is tetrazotised by the dropwise addition of a solution of 6.9 parts of sodium nitrite in 20 parts of water. After stirring for 1 hour at 0-5", the excess nitrous acid is decomposed and the tetrazo solution is poured at 05 into a solution of the sodium salt of 28.8 parts of 1(6-chloro-3-sulfophenyl)- 3-methyl-5-aminopyrazole and parts of crystallised sodium acetate in 500 parts of water. Coupling occurs immediately and the solution turns yellow. The coupling solution is stirred for several hours at 1020, the mineral acid is then bufiered by sprinkling in 30 parts of sodium carbonate, 100 parts of sodium chloride are added to the (VII) The dried dyesuif is a yellow powder which dissolves in hot water with a greenish yellow colour.- It dyes wool from an acetic acid bath at the boil in very level, greenish yellow shades which are fast to wet, alkali and light.

EXAMPLE 2 ll II N HOaS 12.4 parts of 4,4'-diamino-1,l'-diphenylsulphone are tetrazotised as described in Example 1 and the tetrazo solution is added dropwise at Ill-20 to the solution of 25.3 parts of 1-(3'-sulphophenyl)-3-methyl-5-aminopyrazole and 50 parts of crystallised sodium acetate in 500 parts of water. The coupling solution is then stirred for several hours at -20", the mineral acid is buffered by sprinkling in 30 parts of sodium carbonate, the dyestuif solution is heated to 60 and then the disazo dyestuff is salted out with 100 parts of sodium chloride, the precipitate is filtered off under suction and dried in vacuo at 80.

The dry dyestuif is a yellow powder which dissolves in hot water with a yellow colour. The dyestuff dyes wool from an acetic acid liquor on boiling in pure yellow shades which are fast to wet and light.

EXAMPLE 3 15.8 parts'of 2,2'-diamino-4,4-dichloro-1,1-diphenylsulphone in 250 parts of glacial acetic acid are dissolved with 19 parts of concentrated sulfuric acid and the solution is tetrazotised at 5l0 while stirring well with a solution of 6.9 parts of sodium nitrite in 20 parts of water. After stirring for 1 hour at 510, the pale yellowish tetrazo solution is diluted with 500 parts of ice water and is then gradually poured at 0-10 into the solution of the sodium salt of 25.3 parts of l-(4-sulphopenyl)-3-methyl-5-aminopyrazole and 50 parts of crystallised sodium acetate in 600 parts of water. Coupling occurs immediately and the solution turns yellow. The coupling solution is stirred for several hours at 0l0, 100 parts of sodium chloride are added, the precipitated disazo dyestufl? is filtered off and dried.

The dry dyestuff is a yellow powder which dissolves in hot water with a yellow colour. *It dyes wool in the presence of ammonium sulfate at the boil in pure yellow very level shades which are fast to wet and light. The bath is well exhausted.

and the tetrazo-solution is coupled at 10-15" with the solution of the sodium salt of 25.3 parts of 1(3'-sulphophenyl) -3-methyl-5-aminopyrazole and 50 parts of sodium acetate in 500 parts of water. The mixture is stirred for several hours at l0-l5 and then the mineral acid is buffered by sprinkling in 40 parts of sodium carbonate whereupon the disazo dyestuif partly precipitates. The precipitation of the dyestuff is completed by the addition of 100 parts of sodium chloride whereupon it is then EXAMPLE 5 20.4 parts of 3,3'-diamino-1,l-diphenylsulphone-4,4'-

disulphonic acid, in the form of the sodium salt, are dissolved in 500 parts of water, 6.9 parts of sodium nitrate are added and the solution is added dropwise at 0 to 5 while stirring to 30 parts of concentrated hydrochloric acid and 100 parts of ice. After stirring for 1 hour at 0 to 5, the excess nitrous acid is decomposed and the colourless disazo suspension is poured into the solution of 24.2 parts of l-(3',4-dichlorophenyl)-3-methyl-5-aminopyrazole in 400 parts by volume of ethanol. The couplingoccurs immediately and the solution turns yellow. 50 parts of crystallised sodium acetate are added to the coupling mixture which is then stirred for 6 hours at 0 to 10. The dyestufi solution is then diluted with 1000 parts of water, 200 parts of sodium chloride are added and the precipitated yellow disazo dyestuif is filtered otf under suction. The disazo dyestuff is washed with a 10% aqueous solution of sodium chloride and dried in vacuo at 80.

The dyestulf, in the form of a yellow powder, dissolves in hot water with a yellow colour. It dyes wool and synthetic polyamide fibers such as nylon from a boiling bath containing ammonium sulfate in level, pure, greenish yellow shades which are very fast to wet, alkali and light.

EXAMPLE 4 If, instead of the disazo and coupling components given OHa-C-ON=N-C SO-N=N-fiC-GH: V E

ii ii-NH, Nut-o 1H1 I so3H Honsll.6 parts of 4,4-diamino-l,l'-diphenylsulphoxide are in the previous analogous examples, corresponding tetrazotised under the conditions described in Example 1 amounts of the components give'riin the following table 10 oured dyestuff solution and the whole is boiled for 1 hour. 2. A disazo dyestufi": of the formula The solution becomes strongly yellow coloured when the condensation to the disazo dyestufi of the above formula occurs. After cooling the dyestufi solution to 20, the D -Q dyestufi formed is salted out with 200 parts of sodium 5 chloride, filtered off, washed with a 5% aqueous sodium OH3 CO N=N chloride solution and dried. N NHZ H2N-C N The dyestufif is identical with that described in Exampie 2.

EXAMPLE 7 10 --01 o1 100 parts of previously well wetted wool are introduced at 40 into a dyebath which contains, in 3000 parts of water, 2 pans of the disazo dyestuft obtained according to example 2, 10 parts of Glaubers salt and 2 parts of 40% acetic acid. The bath is brought to the boil within 45 minutes and dyeing is performed at the boil for 90 minutes while moving the wool well. After rinsing and G 3 drying, a very level, pure yellow wool dyeing is obtained 0 a Ii 6 N N S02 N N 1i 1i 0H3 which is distinguished by very good fastness properties, NHTC\ particularly to washing, alkali, milling and light. N N

In the same way, the dyestufis given in all the other examples produce fast, level wool dyeing.

EXAMPLE 8 E038 803E 15 3. A disazo dyestuff of the formula 100 parts of previously well wetted wool are introduced at 40 C. into a dyeb ath which contains, in 3000 parts of I v water, 2 parts of the disazo dyestufi obtained according A dlsazo dyestuff of the formula to example 1 and 2 parts of sulphuric acid. The bath is brought to the boil within 45 minutes and dyeing is performed at the boil for 90 minutes while moving the wool 0 I! H II well. After rinsing and drying, a very level, pure yellow wool dyeing is obtained which is distinguished by very N N good fastness properties, particularly to washing, alkali, I I milling and light.

In the same way, the dyestuffs given in all the other examples produce fast, level wool dyeings.

What is claimed is: 1. A member selected from the group consisting of SOaH 03H disazo dyestuffs of the formula OH (}-fiN=N N=N-(H --o-o11, /C NH2 Dig K 1% N (0)n z N/ Y Y1 Y Y;

and the sodium, potassium and ammonium salts thereof, 5, A di d t fl of the f r l wherein Y Z is a member selected from the group consisting of GH3C-CN=N so: N=NC-CGH hydrogen, chlorine, bromine and alkyl with maximal- U, i NH ii I! l 4 carbon atoms NHTC N Y 1 01 Y is a member selected :from the group consisting of f N hydrogen, chlorine, bromine and alkyl with maximally 4 carbon atoms; phenoxy, chlorophenorry, brornophen-oxy, methylphenoxy, phenylsulphonyl, methylphenylsulphonyl, chlorophenylsulphonyl, Y is a member selected from the group consisting of hydrogen, chlorine, bromine, S0311 S0311 g gg fii g g g i g fig fs i References Cited in the file of this patent UNITED STATES PATENTS 2, 19 Exner Dec. 2, 1958 FOREIGN PATENTS 175.217 Germany Sept. 22, 1906 

1. A MEMBER SELECTED FROM THE GROUP CONSISTING OF DISAZO DYESTUFFS OF THE FORMULA 